SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0ed50ceca08797bf2918d766750927e63dcdeb3e8cd3894a08d45c5eedeea54' 
  AND token = 'eQJ8nmoLh/zexvl761z/r+OO7KX0EGKIxyoPYRLtvSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}